From cb04ff9ac424d0e689d9b612e9f73cb443ab4b7e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 8 May 2012 18:56:04 +0200 Subject: [PATCH] sched, perf: Use a single callback into the scheduler We can easily use a single callback for both sched-in and sched-out. This reduces the code footprint in the scheduler path as well as removes the PMU black spot otherwise present between the out and in callback. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-o56ajxp1edwqg6x9d31wb805@git.kernel.org Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 24 ++++++------------------ kernel/events/core.c | 14 ++++++++++---- kernel/sched/core.c | 9 +-------- 3 files changed, 17 insertions(+), 30 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index f325786..8adf70e 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1084,10 +1084,8 @@ extern void perf_pmu_unregister(struct pmu *pmu); extern int perf_num_counters(void); extern const char *perf_pmu_name(void); -extern void __perf_event_task_sched_in(struct task_struct *prev, - struct task_struct *task); -extern void __perf_event_task_sched_out(struct task_struct *prev, - struct task_struct *next); +extern void __perf_event_task_sched(struct task_struct *prev, + struct task_struct *next); extern int perf_event_init_task(struct task_struct *child); extern void perf_event_exit_task(struct task_struct *child); extern void perf_event_free_task(struct task_struct *task); @@ -1207,20 +1205,13 @@ perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) extern struct static_key_deferred perf_sched_events; -static inline void perf_event_task_sched_in(struct task_struct *prev, +static inline void perf_event_task_sched(struct task_struct *prev, struct task_struct *task) { - if (static_key_false(&perf_sched_events.key)) - __perf_event_task_sched_in(prev, task); -} - -static inline void perf_event_task_sched_out(struct task_struct *prev, - struct task_struct *next) -{ perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, NULL, 0); if (static_key_false(&perf_sched_events.key)) - __perf_event_task_sched_out(prev, next); + __perf_event_task_sched(prev, task); } extern void perf_event_mmap(struct vm_area_struct *vma); @@ -1295,11 +1286,8 @@ extern void perf_event_disable(struct perf_event *event); extern void perf_event_task_tick(void); #else static inline void -perf_event_task_sched_in(struct task_struct *prev, - struct task_struct *task) { } -static inline void -perf_event_task_sched_out(struct task_struct *prev, - struct task_struct *next) { } +perf_event_task_sched(struct task_struct *prev, + struct task_struct *task) { } static inline int perf_event_init_task(struct task_struct *child) { return 0; } static inline void perf_event_exit_task(struct task_struct *child) { } static inline void perf_event_free_task(struct task_struct *task) { } diff --git a/kernel/events/core.c b/kernel/events/core.c index 00c58df..e82c7a1 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2039,8 +2039,8 @@ static void perf_event_context_sched_out(struct task_struct *task, int ctxn, * accessing the event control register. If a NMI hits, then it will * not restart the event. */ -void __perf_event_task_sched_out(struct task_struct *task, - struct task_struct *next) +static void __perf_event_task_sched_out(struct task_struct *task, + struct task_struct *next) { int ctxn; @@ -2279,8 +2279,8 @@ static void perf_branch_stack_sched_in(struct task_struct *prev, * accessing the event control register. If a NMI hits, then it will * keep the event running. */ -void __perf_event_task_sched_in(struct task_struct *prev, - struct task_struct *task) +static void __perf_event_task_sched_in(struct task_struct *prev, + struct task_struct *task) { struct perf_event_context *ctx; int ctxn; @@ -2305,6 +2305,12 @@ void __perf_event_task_sched_in(struct task_struct *prev, perf_branch_stack_sched_in(prev, task); } +void __perf_event_task_sched(struct task_struct *prev, struct task_struct *next) +{ + __perf_event_task_sched_out(prev, next); + __perf_event_task_sched_in(prev, next); +} + static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count) { u64 frequency = event->attr.sample_freq; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4603b9d..5c692a0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1913,7 +1913,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) { sched_info_switch(prev, next); - perf_event_task_sched_out(prev, next); + perf_event_task_sched(prev, next); fire_sched_out_preempt_notifiers(prev, next); prepare_lock_switch(rq, next); prepare_arch_switch(next); @@ -1956,13 +1956,6 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) */ prev_state = prev->state; finish_arch_switch(prev); -#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW - local_irq_disable(); -#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ - perf_event_task_sched_in(prev, current); -#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW - local_irq_enable(); -#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ finish_lock_switch(rq, prev); finish_arch_post_lock_switch(); -- 2.7.4